I Have a toyota soarer 1992 1jz auto converted to manual and my car won't rev past 2300rpm here is the list of things i have already done new genuine coolant temp sensor ecu re capped new timing belt and timing checked new fuel pump new fuel filter fuel dampener removed new plugs and coils inspected sometimes the car will rev past but you have to force it, i have searched the forum but no one seems to fix this fault and help would be appreciated thanks !
the loom that was on the auto box when it was bridged ? the car was fine for over a year then developed this fault
Anyone else clued up on 1jz? Engine hasnt been removed or swapped, checked wiring loom today, all seems okay removed all earths and cleaned tried six new coilpacks too im stumped!
Maybe you just have a really slow underpowered 1jz? lol honestly I'd start at the neutral switch and then the coils... if like you say you have already done that have you had it mapped before? Or the engine has gone into limp mode? I don't really know the 1jz but this is a friendly bump if not much else
So have you done anything to actually diagnose the problem, rather than just throwing parts at it ? Are there any fault codes coming up ? If you dont have a suitable scanner, older Toyotas can generally give flash codes. And is it a total engine cut, is it exactly the same rpm, same hot or cold, anything else happening ? Some details would be helpful. Have you checked to ensure coils/injectors are maintaining power etc during this ? etc etc the list of basic things to check could go on......things you do before randomly throwing parts at it
Thanks for the replys, tested tps sensor and was faulty, replaced with working one and calibrated it, engine still the same doesnt rev past 2300 when cold but once it warms up it seems fine, havnt tested injectors but have swapped all 6 coilpacks with new ones and still the same
Update. Tested injector wiring, when fault happens no live is at injectors almost like a fuel cut at exactly 2100rpm, also done a diagnostics on car says no faults in efi any ideas?
That would seem a far cry from the original description of the problem. 12v supply for injectors comes via the car wiring, it has little to do with the ecu. In short, if the key is turned on, then via relays/fuses that wire should have 12v and chances are it also supplies other items. But obviously you'd need to see whoever wired the car, or what alterations etc may have been made by anyone. An ecu controlled fuel cut would not cut the live/12v to anything, it would simply stop triggering the injectors which as with all ecu's are ground triggered.
plug gaps are all okay, I plugged a noid tester onto injectors and light stopped flashing when fault happens so assumed it was live but could be switched earth, what would cause the earth cut then ?
Assumptions will never be helpful when trying to diagnose problems. So you're now saying there is a reliable 12v supply to the injectors at all times when there should be ? The ecu controls the ground trigger to each injector, it's how fuel supply is regulated. So again it comes back to needing to diagnose the problem instead of just throwing parts at it and hoping. See post #7, none of the questions have been answered that were asked several weeks ago. And what does the rev counter do during this problem ?
I have said i done a diagnostics on the car and it said no faults... I havnt chucked parts at it i changed things that needed changing anyway such as timing belt fuel filters etc I havnt tested if there is a live at the injectors, i plugged in a noid tester to make sure injectors are getting there feed and they flash until the fault happens at around 2100rpm ish hot or cold the light stops flashing showing some sort of cut to the injector when fault happens. Rev gauge works fine but once car hits 2100rpm the revs drop and you cant rev the car back up till it hits idle again then you can rev it back up to 2100 and so on
Sounds possibly like fuel cut from over boost, do the watergate actuators move freely? Assuming it still has standard twins? Does the car have an exhaust?
Given the lack of info, and lack of ability to test what is asked. Change the crank sensor. ideally you would test both crank/cam triggers with a scope...but it's unlikely you will be doing that when you dont seem to have a basic multimeter to test other stuff correctly. But a problem with the crank sensor is more likely than other things based on what I'm picking up from you, although often this can change with temperature, which you seem to suggest it does not. Also it seems unclear when you're saying this fault developed, as you do seem to suggest it ran fine at some point ? So did this happen overnight, or get worse over time, or was specific work carried out and the fault there immediately after ?
haven't looked at the actuators on the turbo but will look, yes it ran fine then went into storage for a year thats when it developed the fault, ill try and test all sensors cam and crank with a scope when i get back to unit
check if neutral pin is grounded http://wilbo666.pbworks.com/w/page/47216384/1JZ-GTE JZZ30 Soarer Engine Wiring
